The expansion agents can only make up the shrinkage to some extent, and the compensation effects would be reduced when the retardener and fly - ash are used. the expansion agents are not panaceas to avoid the shrinkage cracking as expansion can also reduce the concrete soundness. under bad curing condition, the polypropylene fibrillated film fiber can improve concrete ' s anti - crarking property, while the nominal steels have very unobvious effects. to reduce the concrete shrinkage thus avoid the cracking, the former factors must all be taken into account in concrete proportion design to develop sound concrete
研究結果表明,水泥的品種和用量是影響混凝土收縮值的主要因素之一,當混凝土中水泥用量超過470kg / m ~ 3時,混凝土的收縮值超過400 10 ~ ( - 6 ) ,在約束狀態下存在高開裂風險;採用細
砂使混凝土單位用水量顯著提高,收縮值也大幅增加;優質粉
煤灰總體上能抑制混凝土的收縮,以超量方式摻入其抑制作用更加明顯,但粉
煤灰混凝土早期的粘聚性較差,應注意養護,以免失水產生龜裂;早強減水劑和緩凝減水劑都會使混凝土收縮值增加;膨脹劑只能補償混凝土部分收縮,同時受緩凝劑和粉
煤灰的抑制,而且膨脹使混凝土的體積安定性增加了不確定因素,膨脹劑不是解決混凝土收縮裂縫的良方。
In this paper, the effects of fly ash, cement, lime, fine sands, foam agent, w / c ratio and additional agent on foamed concrete were studied by experiments, the best combination ratio of fly ash foamed concrete whose density varies from 551kg / m3 to 650kg / m3 was obtained through orthogonal test design, the foam agent quantity and the fly ash quantity effect the fly ash foamed concrete greatly, so the author selected them as independents to establish duality linear regression equations, the equations were quite ideal through the test of model summary r. moreover, the author also did some experiments about the water resistance of magnesium oxychloride cement fly ash foamed concrete, the outcome showed that phosphoric acid has good effect on water resistance, and its appropriate quantity was found
本文通過試驗研究了粉
煤灰、水泥、石灰、細
砂、發泡液、水灰比及外加劑對粉
煤灰發泡混凝土性能的影響,採用正交設計試驗方法得出了600級粉
煤灰發泡混凝土的最佳配合比,同時發現發泡液和粉
煤灰摻量對發泡混凝土的影響最為顯著,因此,以二者為自變量建立了二元線性回歸方程,通過全相關系數的檢驗發現方程較為理想。此外,還對氯氧鎂水泥基粉
煤灰發泡混凝土的耐水性進行了相關實驗,發現磷酸有較好的耐水性效果,同時找到了其合適的摻量范圍。
Changes of the longitudinal and transversal wave velocities in different directions and the rock velocity anisotropy as a function of confining pressure have been studied under laboratory ultrasonic frequency for shale and sandstone with marked foliation, which had been saturated by the fluids with different viscosity kerosene and vacuum pump oil and salinity distilled water, 50000
利用不同黏度
煤油和真空泵油不同礦化度蒸餾水50mg l和150mg l的nacl溶液的流體對頁巖和具有明顯層理的
砂巖進行飽和,在實驗室超聲頻率下研究樣品不同方向縱橫波速度以及各向異性參數
The effects of different drawing interval and top - coal fragmental size on flow character of coal - gangue and sand, and on mixed degree of coal and gangue were analyzed during drawing top - coal
分析了不同放
煤步距、頂
煤塊度對放
煤過程中
煤矸
砂流動形態、混矸程度的影響。
Test mothod for effective bentonite and effective seacoal content in green molding sand
鑄造用濕型
砂有效膨潤土及有效
煤粉。試驗方法
Main factors and mechanics influencing water inrush from roof snadstone
影響徐州礦區
煤層頂板
砂巖涌水的主要因素及機理
The business scope covers the logistics services such as handling, storage, piling and transportation of containers, break - bulk ( such as logs, planks, pta, pea and steels ), bulks ( such as coals, iron ores and sand, etc ) and the liquidized chemical products
業務范圍包括集裝箱、件雜貨(原木、板材、 pta 、 pea 、鋼材等) 、散貨(
煤炭、鐵礦、
砂等)和液體化工產品的裝卸、倉儲、堆存、運輸等港口綜合物流服務。
Jiangmen boasts of rich mineral resources with 37 kinds of minable minerals, including limestone, silica sand, potassium feldspar, monazite, crystal, aquamarine, coal, tombarthite / rare earth, gold, silver, copper, iron, stannum and tungsten, among others
礦產資源豐富,已探明可開採的有石灰石、硅
砂、鉀長石、獨居石、水晶、綠柱石、
煤、稀土及金、銀、銅、鐵、錫、鎢等37種。
On the basis of the concept and analysis method of slope geological structure, four typical slope geological structures are selected by some investigations on more than one hundred high rock slopes in the motorway project. these structures are thick sandstone stratum, stratum including weak coal, stratum made of red or brown plastic clay and soft rock mass and stratum made of remnants rock mass. the practical slope geological structures are compact basis of geological mechanical model for the analysis of relaxation zone in high rock slope projects
在介紹了坡體結構概念並提出建立坡體結構方法的基礎上,根據對京珠高速公路粵境北段路塹高邊坡工程中百余處巖石高邊坡的調查總結,選擇了其中較為具有代表意義的厚層
砂巖、
煤系地層、紅土地層及殘坡積層路塹高邊坡共4類巖石高邊坡作為研究對象,為對巖石高邊坡開挖鬆弛區的分析打下了堅實的實際地質力學模型基礎。
The activatory coal gangue powder ( acgp ), ground cement clinker and natural gypsum are mixed by different ratios to prepare blended cement specimens, and its mortar compressive strength performance, water usage for standard consistency, and flowability of mortar are investigated
摘要將經燃燒等過程進行活化處理的
煤矸石細粉與磨至一定比表面積的水泥熟料及天然生石膏混合均勻,製成了活化謀矸石粉摻量比例不同的多組混合水泥,並對其膠
砂強度性能、標準稠度用水量、膠
砂流動度進行了實驗檢測。
On the basis of research of various physical characteristics of coal gangue, fly ash, aeolian sand, through contrast experiment, we chose this new reinforce material
在對
煤矸石、粉
煤灰和風積
砂土的各項物理力學特性進行試驗研究的基礎上,通過對比試驗選擇了可供工程應用的新型固化劑。
This paper first discusses the cause of crack formation and crack mechanism of high performance concrete. then carries out crack tests of three groups of concrete slabs using aggregate type, sand rate and dosage of fly ash as design parameter
本文初步探討了泵送高流態混凝土的裂縫成因和開裂機理,並分別以骨料品種、
砂率以及粉
煤灰摻量為設計參數進行了三組配合比混凝土平板的抗裂試驗。
Anti penetration of hardened mortar can reach 10 - 7cm / s. adopting sulfate - aluminum cement, phosphorus slag, flying ash, yellow slag and ect raw materials, the optimized mixture program of dmm is a3b3c2 ( cement 480 m2 / kg, phosphorus slag352 m2 / kg, activated agent 3 % ), 28 strength is low, due to cement alkality, resulting in activity of phosphorus slag and flying ash small
採用硫鋁酸鹽水泥,磷渣、粉
煤灰、黃
砂等原武漢理工大學碩士學位論文料配製抗滲干拌
砂漿最優配料方案為: a3b3c2 (水泥比表面積4som , / kg ,磷渣比表面積352mz / kg ,激發劑3 % ) 。
Place the house sponge on the cinder block and place the brick with the carpenter ' s sponge, sand paper and duct tape on top of the sponge
將家用海綿放在空心渣
煤磚上(作桌子用) ,上面依次放置磚頭、木匠用海綿、
砂紙和膠帶在海綿之上。
Preparation of steel substrates before application of paints and related products - specifications for non - metallic blast - cleaning abrasives - coal furnace slag
塗料和其它相關產品應用前鋼基體的預處理.非金屬噴
砂清理磨料規范.
煤爐熔渣
Based on the geological and mining conditions and occurrence characteristics of loose aquifer of xinglongzhuang colliery, water bursting cause of 4303 full - mechanized caving mining face under loose aquifer was analyzed, the prevention measures of the 3rd aquifer and reasonable dimension of coal pillar for sand proof were discussed in this paper
摘要根據興隆莊煤礦地質采礦條件,結合鬆散含水層賦存特徵,分析了四采區4303綜放工作面第四系鬆散含水層出水的原因,探討了防治三含水的技術途徑和留設防砂煤柱的合理尺寸。